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* GFS2: Make sure rindex is uptodate before starting transactionsBob Peterson2012-04-051-2/+11
| | | | | | | | | This patch removes the call from gfs2_blk2rgrd to function gfs2_rindex_update and replaces it with individual calls. The former way turned out to be too problematic. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: FITRIM ioctl supportSteven Whitehouse2012-02-281-2/+2
| | | | | | | | | | | | | | | | | | | | | The FITRIM ioctl provides an alternative way to send discard requests to the underlying device. Using the discard mount option results in every freed block generating a discard request to the block device. This can be slow, since many block devices can only process discard requests of larger sizes, and also such operations can be time consuming. Rather than using the discard mount option, FITRIM allows a sweep of the filesystem on an occasional basis, and also to optionally avoid sending down discard requests for smaller regions. In GFS2 FITRIM will work at resource group granularity. There is a flag for each resource group which keeps track of which resource groups have been trimmed. This flag is reset whenever a deallocation occurs in the resource group, and set whenever a successful FITRIM of that resource group has taken place. This helps to reduce repeated discard requests for the same block ranges, again improving performance. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Read resource groups on mountSteven Whitehouse2012-02-281-11/+3
| | | | | | | | | | | | | This makes mount take slightly longer, but at the same time, the first write to the filesystem will be faster too. It also means that if there is a problem in the resource index, then we can refuse to mount rather than having to try and report that when the first write occurs. In addition, to avoid recursive locking, we hvae to take account of instances when the rindex glock may already be held when we are trying to update the rbtree of resource groups. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Read in rindex if necessary during unlinkBob Peterson2012-02-281-2/+7
| | | | | | | | | | This patch fixes a problem whereby you were unable to delete files until other file system operations were done (such as statfs, touch, writes, etc.) that caused the rindex to be read in. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Fix nlink setting on inode creationSteven Whitehouse2012-01-111-3/+1
| | | | | | | | Since the nlink count will be 0, we need to use set_nlink rather than inc_nlink in order to avoid triggering the inc_nlink warning which was added recently. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmwLinus Torvalds2012-01-081-35/+37
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw: GFS2: local functions should be static GFS2: We only need one ACL getting function GFS2: Fix multi-block allocation GFS2: decouple quota allocations from block allocations GFS2: split function rgblk_search GFS2: Fix up "off by one" in the previous patch GFS2: move toward a generic multi-block allocator GFS2: O_(D)SYNC support for fallocate GFS2: remove vestigial al_alloced GFS2: combine gfs2_alloc_block and gfs2_alloc_di GFS2: Add non-try locks back to get_local_rgrp GFS2: f_ra is always valid in dir readahead function GFS2: Fix very unlikley memory leak in ACL xattr code GFS2: More automated code analysis fixes GFS2: Add readahead to sequential directory traversal GFS2: Fix up REQ flags
| * GFS2: local functions should be staticH Hartley Sweeten2011-12-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | Quiets the sparse noise: warning: symbol 'gfs2_initxattrs' was not declared. Should it be static? Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Fix multi-block allocationSteven Whitehouse2011-11-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clean up gfs2_alloc_blocks so that it takes the full extent length rather than just the number of non-inode blocks as an argument. That will only make a difference in the inode allocation case for now. Also, this fixes the extent length handling around gfs2_alloc_extent() so that multi block allocations will work again. The rd_last_alloc block is set to the final block in the allocated extent (as per the update to i_goal, but referenced to a different start point). This also removes the dinode argument to rgblk_search() which is no longer used. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: decouple quota allocations from block allocationsBob Peterson2011-11-221-30/+28
| | | | | | | | | | | | | | | | | | | | | | | | This patch separates the code pertaining to allocations into two parts: quota-related information and block reservations. This patch also moves all the block reservation structure allocations to function gfs2_inplace_reserve to simplify the code, and moves the frees to function gfs2_inplace_release. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: move toward a generic multi-block allocatorBob Peterson2011-11-211-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is a revision of the one I previously posted. I tried to integrate all the suggestions Steve gave. The purpose of the patch is to change function gfs2_alloc_block (allocate either a dinode block or an extent of data blocks) to a more generic gfs2_alloc_blocks function that can allocate both a dinode _and_ an extent of data blocks in the same call. This will ultimately help us create a multi-block reservation scheme to reduce file fragmentation. This patch moves more toward a generic multi-block allocator that takes a pointer to the number of data blocks to allocate, plus whether or not to allocate a dinode. In theory, it could be called to allocate (1) a single dinode block, (2) a group of one or more data blocks, or (3) a dinode plus several data blocks. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: combine gfs2_alloc_block and gfs2_alloc_diBob Peterson2011-11-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | GFS2 functions gfs2_alloc_block and gfs2_alloc_di do basically the same things, with a few exceptions. This patch combines the two functions into a slightly more generic gfs2_alloc_block. Having one centralized block allocation function will reduce code redundancy and make it easier to implement multi-block reservations to reduce file fragmentation in the future. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: More automated code analysis fixesSteven Whitehouse2011-11-081-3/+6
| | | | | | | | | | | | | | | | A potentially uninitialised variable, some unreachable code, and the main part of this, fixing the error path in the unlink function. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* | fs: propagate umode_t, misc bitsAl Viro2012-01-031-5/+5
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | switch ->mknod() to umode_tAl Viro2012-01-031-1/+1
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | switch ->create() to umode_tAl Viro2012-01-031-1/+1
| | | | | | | | | | | | | | | | vfs_create() ignores everything outside of 16bit subset of its mode argument; switching it to umode_t is obviously equivalent and it's the only caller of the method Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | switch vfs_mkdir() and ->mkdir() to umode_tAl Viro2012-01-031-1/+1
|/ | | | | | | vfs_mkdir() gets int, but immediately drops everything that might not fit into umode_t and that's the only caller of ->mkdir()... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge http://sucs.org/~rohan/git/gfs2-3.0-nmwLinus Torvalds2011-10-281-74/+38
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * http://sucs.org/~rohan/git/gfs2-3.0-nmw: (24 commits) GFS2: Move readahead of metadata during deallocation into its own function GFS2: Remove two unused variables GFS2: Misc fixes GFS2: rewrite fallocate code to write blocks directly GFS2: speed up delete/unlink performance for large files GFS2: Fix off-by-one in gfs2_blk2rgrpd GFS2: Clean up ->page_mkwrite GFS2: Correctly set goal block after allocation GFS2: Fix AIL flush issue during fsync GFS2: Use cached rgrp in gfs2_rlist_add() GFS2: Call do_strip() directly from recursive_scan() GFS2: Remove obsolete assert GFS2: Cache the most recently used resource group in the inode GFS2: Make resource groups "append only" during life of fs GFS2: Use rbtree for resource groups and clean up bitmap buffer ref count scheme GFS2: Fix lseek after SEEK_DATA, SEEK_HOLE have been added GFS2: Clean up gfs2_create GFS2: Use ->dirty_inode() GFS2: Fix bug trap and journaled data fsync GFS2: Fix inode allocation error path ...
| * GFS2: Cache the most recently used resource group in the inodeSteven Whitehouse2011-10-211-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This means that after the initial allocation for any inode, the last used resource group is cached in the inode for future use. This drastically reduces the number of lookups of resource groups in the common case, and this the contention on that data structure. The allocation algorithm is the same as previously, except that we always check to see if the goal block is within the cached rgrp first before going to the rbtree to look one up. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Make resource groups "append only" during life of fsSteven Whitehouse2011-10-211-13/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since we have ruled out supporting online filesystem shrink, it is possible to make the resource group list append only during the life of a super block. This gives several benefits: Firstly, we only need to read new rindex elements as they are added rather than needing to reread the whole rindex file each time one element is added. Secondly, the rindex glock can be held for much shorter periods of time, and is completely removed from the fast path for allocations. The lock is taken in shared mode only when updating the resource groups when the first allocation occurs, and after a grow has taken place. Thirdly, this results in a reduction in code size, and everything gets a lot simpler to understand in this area. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Clean up gfs2_createSteven Whitehouse2011-10-211-22/+14
| | | | | | | | | | | | | | | | | | If we pass through knowledge of whether the creation is intended to be exclusive or not, then we can deal with that in gfs2_create_inode and remove one set of locking. Also this removes the loop in gfs2_create and simplifies the code a bit. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Use ->dirty_inode()Steven Whitehouse2011-10-211-30/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The aim of this patch is to use the newly enhanced ->dirty_inode() super block operation to deal with atime updates, rather than piggy backing that code into ->write_inode() as is currently done. The net result is a simplification of the code in various places and a reduction of the number of gfs2_dinode_out() calls since this is now implied by ->dirty_inode(). Some of the mark_inode_dirty() calls have been moved under glocks in order to take advantage of then being able to avoid locking in ->dirty_inode() when we already have suitable locks. One consequence is that generic_write_end() now correctly deals with file size updates, so that we do not need a separate check for that afterwards. This also, indirectly, means that fdatasync should work correctly on GFS2 - the current code always syncs the metadata whether it needs to or not. Has survived testing with postmark (with and without atime) and also fsx. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| * GFS2: Fix inode allocation error pathSteven Whitehouse2011-10-211-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we have got far enough through the inode allocation code path that an inode has already been allocated, then we must call iput to dispose of it, if an error occurs during a later part of the process. This will always be the final iput since there will be no other references to the inode. Unlike when the inode has been unlinked, its block state will be GFS2_BLKST_INODE rather than GFS2_BLKST_UNLINKED so we need to skip the test in ->evict_inode() for this one case in order to ensure that it will be deallocated correctly. This patch adds a new flag in order to ensure that this will happen correctly. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* | Merge branch 'next-evm' of ↵James Morris2011-08-091-20/+18
|\ \ | |/ |/| | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/zohar/ima-2.6 into next Conflicts: fs/attr.c Resolve conflict manually. Signed-off-by: James Morris <jmorris@namei.org>
| * security: new security_inode_init_security API adds function callbackMimi Zohar2011-07-181-20/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch changes the security_inode_init_security API by adding a filesystem specific callback to write security extended attributes. This change is in preparation for supporting the initialization of multiple LSM xattrs and the EVM xattr. Initially the callback function walks an array of xattrs, writing each xattr separately, but could be optimized to write multiple xattrs at once. For existing security_inode_init_security() calls, which have not yet been converted to use the new callback function, such as those in reiserfs and ocfs2, this patch defines security_old_inode_init_security(). Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
* | fs: take the ACL checks to common codeChristoph Hellwig2011-07-251-3/+3
| | | | | | | | | | | | | | | | | | Replace the ->check_acl method with a ->get_acl method that simply reads an ACL from disk after having a cache miss. This means we can replace the ACL checking boilerplate code with a single implementation in namei.c. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | simplify gfs2_lookup()Al Viro2011-07-201-11/+3
| | | | | | | | | | | | d_splice_alias() will DTRT when given NULL or ERR_PTR Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | ->permission() sanitizing: don't pass flags to ->permission()Al Viro2011-07-201-8/+8
| | | | | | | | | | | | not used by the instances anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | ->permission() sanitizing: don't pass flags to generic_permission()Al Viro2011-07-201-1/+1
| | | | | | | | | | | | | | redundant; all callers get it duplicated in mask & MAY_NOT_BLOCK and none of them removes that bit. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | kill check_acl callback of generic_permission()Al Viro2011-07-201-1/+4
|/ | | | | | | its value depends only on inode and does not change; we might as well store it in ->i_op->check_acl and be done with that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* GFS2: Move all locking inside the inode creation functionSteven Whitehouse2011-05-131-132/+52
| | | | | | | | | Now that there are no longer any exceptions to the normal inode creation code path, we can move the parts of the locking code which were duplicated in mkdir/mknod/create/symlink into the inode create function. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Clean up symlink creationSteven Whitehouse2011-05-131-36/+29
| | | | | | | | | This moves the symlink specific parts of inode creation into the function where we initialise the rest of the dinode. As a result we have one less place where we need to look up the inode's buffer. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Clean up mkdirSteven Whitehouse2011-05-131-44/+33
| | | | | | | | This moves the initialisation of the directory into the inode creation functions to avoid having to duplicate the lookup of the inode's buffer. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Rename ops_inode.c to inode.cSteven Whitehouse2011-05-101-0/+1990
| | | | | | | | This is the final part of the ops_inode.c/inode.c reordering. We are left with a single file called inode.c which now contains all the inode operations, as expected. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Inode.c is empty now, remove itSteven Whitehouse2011-05-101-38/+0
| | | | Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Move final part of inode.c into super.cSteven Whitehouse2011-05-091-36/+0
| | | | | | Now inode.c is empty. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Move most of the remaining inode.c into ops_inode.cSteven Whitehouse2011-05-091-711/+0
| | | | | | | | | | This is in preparation to remove inode.c and rename ops_inode.c to inode.c. Also most of the functions which were left in inode.c relate to the creation and lookup of inodes. I'm intending to work on consolidating some of that code, and its easier when its all in one place. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Move gfs2_refresh_inode() and friends into glops.cSteven Whitehouse2011-05-091-117/+0
| | | | | | | Eventually there will only be a single caller of this code, so lets move it where it can be made static at some future date. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Remove gfs2_dinode_print() functionSteven Whitehouse2011-05-091-23/+1
| | | | | | | | | | This function was intended for debugging purposes, but it is not very useful. If we want to know what is on disk then all we need is a block number and gfs2_edit can give us much better information about what is there. Otherwise, if we are interested in what is stored in the in-core inode, it doesn't help us out there either. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: When adding a new dir entry, inc link count if it is a subdirSteven Whitehouse2011-05-091-47/+1
| | | | | | | | | | | | This adds an increment of the link count when we add a new directory entry, if that entry is itself a directory. This means that we no longer need separate code to perform this operation. Now that both adding and removing directory entries automatically update the parent directory's link count if required, that makes the code shorter and simpler than before. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Double check link count under glockSteven Whitehouse2011-05-051-7/+28
| | | | | | | | | | | | | | | | | | | To avoid any possible races relating to the link count, we need to recheck it under the inode's glock in all cases where it matters. Also to ensure we never get any nasty surprises, this patch also ensures that once the link count has hit zero it can never be elevated by rereading in data from disk. The only place we cannot provide a proper solution is in rename in the case where we are removing a target inode and we discover that the target inode has been already unlinked on another node. The race window is very small, and we return EAGAIN in this case to indicate what has happened. The proper solution would be to move the lookup parts of rename from the vfs into library calls which the fs could call directly, but that is potentially a very big job and this fix should cover most cases for now. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Make writeback more responsive to system conditionsSteven Whitehouse2011-04-201-2/+2
| | | | | | | | | | | | | | | This patch adds writeback_control to writing back the AIL list. This means that we can then take advantage of the information we get in ->write_inode() in order to set off some pre-emptive writeback. In addition, the AIL code is cleaned up a bit to make it a bit simpler to understand. There is still more which can usefully be done in this area, but this is a good start at least. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Optimise glock lru and end of life inodesSteven Whitehouse2011-04-201-59/+0
| | | | | | | | | | | | | | | | | | | | | The GLF_LRU flag introduced in the previous patch can be used to check if a glock is on the lru list when a new holder is queued and if so remove it, without having first to get the lru_lock. The main purpose of this patch however is to optimise the glocks left over when an inode at end of life is being evicted. Previously such glocks were left with the GLF_LFLUSH flag set, so that when reclaimed, each one required a log flush. This patch resets the GLF_LFLUSH flag when there is nothing left to flush thus preventing later log flushes as glocks are reused or demoted. In order to do this, we need to keep track of the number of revokes which are outstanding, and also to clear the GLF_LFLUSH bit after a log commit when only revokes have been processed. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: filesystem hang caused by incorrect lock orderBob Peterson2011-04-181-15/+41
| | | | | | | | | | | | | | This patch fixes a deadlock in GFS2 where two processes are trying to reclaim an unlinked dinode: One holds the inode glock and calls gfs2_lookup_by_inum trying to look up the inode, which it can't, due to I_FREEING. The other has set I_FREEING from vfs and is at the beginning of gfs2_delete_inode waiting for the glock, which is held by the first. The solution is to add a new non_block parameter to the gfs2_iget function that causes it to return -ENOENT if the inode is being freed. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* Merge branch 'master' of git://git.infradead.org/users/eparis/selinux into nextJames Morris2011-03-081-3/+4
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| * fs/vfs/security: pass last path component to LSM on inode creationEric Paris2011-02-011-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SELinux would like to implement a new labeling behavior of newly created inodes. We currently label new inodes based on the parent and the creating process. This new behavior would also take into account the name of the new object when deciding the new label. This is not the (supposed) full path, just the last component of the path. This is very useful because creating /etc/shadow is different than creating /etc/passwd but the kernel hooks are unable to differentiate these operations. We currently require that userspace realize it is doing some difficult operation like that and than userspace jumps through SELinux hoops to get things set up correctly. This patch does not implement new behavior, that is obviously contained in a seperate SELinux patch, but it does pass the needed name down to the correct LSM hook. If no such name exists it is fine to pass NULL. Signed-off-by: Eric Paris <eparis@redhat.com>
* | GFS2: Fix error path in gfs2_lookup_by_inum()Steven Whitehouse2011-01-181-50/+22
|/ | | | | | | | | | | | | | | In the (impossible, except if there is fs corruption) error path in gfs2_lookup_by_inum() if the call to gfs2_inode_refresh() fails, it was leaving the function by calling iput() rather than iget_failed(). This would cause future lookups of the same inode to block forever. This patch fixes the problem by moving the call to gfs2_inode_refresh() into gfs2_inode_lookup() where iget_failed() is part of the error path already. Also this cleans up some unreachable code and makes gfs2_set_iop() static. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* Merge branch 'vfs-scale-working' of ↵Linus Torvalds2011-01-071-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin * 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits) fs: scale mntget/mntput fs: rename vfsmount counter helpers fs: implement faster dentry memcmp fs: prefetch inode data in dcache lookup fs: improve scalability of pseudo filesystems fs: dcache per-inode inode alias locking fs: dcache per-bucket dcache hash locking bit_spinlock: add required includes kernel: add bl_list xfs: provide simple rcu-walk ACL implementation btrfs: provide simple rcu-walk ACL implementation ext2,3,4: provide simple rcu-walk ACL implementation fs: provide simple rcu-walk generic_check_acl implementation fs: provide rcu-walk aware permission i_ops fs: rcu-walk aware d_revalidate method fs: cache optimise dentry and inode for rcu-walk fs: dcache reduce branches in lookup path fs: dcache remove d_mounted fs: fs_struct use seqlock fs: rcu-walk for path lookup ...
| * fs: provide rcu-walk aware permission i_opsNick Piggin2011-01-071-2/+2
| | | | | | | | Signed-off-by: Nick Piggin <npiggin@kernel.dk>
* | GFS2: Remove unreachable calls to vmtruncateSteven Whitehouse2010-11-301-9/+0
|/ | | | | Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Fix inode deallocation raceSteven Whitehouse2010-11-151-117/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | This area of the code has always been a bit delicate due to the subtleties of lock ordering. The problem is that for "normal" alloc/dealloc, we always grab the inode locks first and the rgrp lock later. In order to ensure no races in looking up the unlinked, but still allocated inodes, we need to hold the rgrp lock when we do the lookup, which means that we can't take the inode glock. The solution is to borrow the technique already used by NFS to solve what is essentially the same problem (given an inode number, look up the inode carefully, checking that it really is in the expected state). We cannot do that directly from the allocation code (lock ordering again) so we give the job to the pre-existing delete workqueue and carry on with the allocation as normal. If we find there is no space, we do a journal flush (required anyway if space from a deallocation is to be released) which should block against the pending deallocations, so we should always get the space back. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>